TORONTO - A UFC card stacked with big men has been tainted by a positive drug test from one of the biggest.

The Nevada State Athletic Commission says Dutch heavyweight Alistair Overeem, a six-foot-five 263-pound man-mountain who is one of the sport's biggest names, tested positive for an increased testosterone-epitestosterone ratio.

Most people are a ratio of 1-1 although the commission allows for a ratio of 6-1. Commission executive director Keith Kizer said Overeem's urine test showed more than 10-1.

Since Overeem is currently without a license to fight — his last one expired at the end of 2011 — he will have to appear before the Nevada commission to get a new one.

That throws his UFC 146 title fight with champion Junior Dos Santos in jeopardy. The main event was one of five heavyweight matchups planned for the main card May 26 in Las Vegas.

"I am beyond pissed about this," UFC president Dana White told a previously arranged conference call with Canadian reporters Wednesday. "He was in my office I don't know how long ago and looked me and Lorenzo (co-owner Lorenzo Fertitta) in the face and said . . . 'Absolutely, I'm clean. I'll pass the test.'"

"It's disgusting," he added.

White said he was so angry he would let Fertitta deal with the fighter.

"I don't want to talk to him."

The UFC boss said a positive test was a "career killer," adding the Dutch fighter could lose "a lot of money."

Overeem, a former Strikeforce champion with a 36-11-1 record, made his UFC debut Dec. 30 at UFC 141 when he knocked out Brock Lesnar in the first round for the right to meet Dos Santos.

Typically, fighters' licenses expire at the end of the calendar year. They then have to apply for a new one, with updated medicals and drug tests.

Had Overeem been licensed, the Nevada commission would have filed a disciplinary complaint. That puts the burden of proof on the commission.

For licensing, the athlete has the burden of demonstrating he should be allowed to fight, according to Kizer.

In the wake of the positive test, Overeem now has three options, according to Kizer.

He can just move on and not fight.

He can ask for his B sample to be tested. "If that came back negative, I would give him a license," Kizer said.

The final option is to come before the commission and "argue 'Hey despite my positive test, you should still license me because ...'"

Kizer expects the second option. "I'm sure he'll have the B sample tested and if it comes back positive as well, I don't think we'll hear from him again."

Rather than sanction Overeem, the commission would deny him a license to fight should it not be won over by his arguments.

"The effect is the same," said Kizer.

Overeem could reapply in the future.

Overeem, a star in Pride, Strikeforce and K-1, arrived in the UFC last year with baggage.

Things got complicated with a pre-Lesnar fight drug test when Overeem left the U.S. during his training camp to visit his ailing mother in the Netherlands.

The fighter got a blood test done, which came back normal for testosterone and other levels. But Kizer asked for a urine test — which is used to check the testosterone-epitestosterone ratio — because steroids stay in your urine longer.

Overeem eventually did the urine test but his doctor did not include all the proper forms. As a result, the lab rejected the sample. Three weeks after Kizer's original request, Overeem flew to England and provided a urine sample at an accredited lab that came back negative.

He was tested again when he flew to Vegas some weeks later and was also tested fight night. Overeem passed all three urine tests and the one blood test.

Overeem got his license to fight in Nevada but the drama — and his change in body type over the years — left people talking.

"He's been fielding nothing but steroid questions all day," one of his handlers told a journalist before a UFC 141 interview.

Overeem used to fight at 205 pounds as a light-heavyweight, walking around at 215-220 pounds. Now he is right at the edge of the 265-pound heavyweight limit.

He attributes the weight increase to strength and conditioning training and diet.

Overeem is unbeaten in 12 fights, a stretch dating back to a September 2007 loss in K-1 to Sergei Kharitonov.

The UFC has tried to combat illegal drugs, testing fighters when they sign contracts. Commissions also do random testing in addition to tests around fights.

Anyone doping in MMA is "an absolute total moron," White said.

"You know you're being tested. . . . It's beyond comprehension."

Overeem was sentenced to 50 hours of community service and anger-management counselling last month for allegedly pushing a woman at a Las Vegas nightclub.

Overeem, who now lives in Miami, travels with a security detail to avoid any future incidents.

Mir, who is slated to fight Velasquez, was quick to offer his services as a replacement for Overeem in the main event.

"I have been fortunate to be able to fight in the UFC for more than a decade, and it is a dream of mine to become the first three-time heavyweight champion in the UFC," Mir said in a statement. "Being able to fight Junior Dos Santos would put me one step closer to that dream."